Integrated circuit device designers constantly strive to create active devices such as transistors that are as small as possible. One of the chief limiting dimensions in a transistor design is the size of the control gate of the device. A variety of techniques have been used to reduce the size of the control gate of a transistor including the use of disposable gate production techniques. These techniques have been successful in reducing the lateral dimension of a control gate of a transistor to 500 Angstroms or less.
With a decrease in the lateral dimension of a transistor, the overall amount of material in the control gate is correspondingly decreased. This results in a reduction of the ability of the control gate to carry current. This problem cannot be addressed directly by solely using lower resistance materials in the control gate because the threshold voltage of the device is directly related to the work function of the material used in the gate of the device. For example, in the context of silicon-based CMOS applications, it is advantageous for the overall function of the device to have polysilicon or other silicon materials in the control gate of the device adjacent the gate insulator of the device.